(a) Field of the Invention
Exemplary embodiments of the present invention relate to a hydrogen tank (bombe), and particularly, to a method for managing a temperature anomaly in a hydrogen tank, which compares detected temperature values of a plurality of temperature sensors with each other and accurately checks whether a specific temperature sensor is abnormal to improve the reliability of the result of a control logic utilizing detected temperature values and secure the safety of a motor vehicle, and a system for the same.
(b) Description of Related Art
In general, since hydrogen that chemically reacts with oxygen is employed as fuel in a hydrogen fuel cell motor vehicle, a hydrogen storage system including a hydrogen tank (or bombe) is mounted to the motor vehicle.
In general, in view of a performance aspect, a high pressure of 700 bars is applied as an allowable pressure of the hydrogen tank, and a temperature between −40° C. and 85° C. is applied as an allowable temperature of the hydrogen tank. In particular, the temperature in the hydrogen tank should not exceed 85° C. for safety reasons when the hydrogen tank is filled with hydrogen.
For this reason, a temperature sensor for detecting internal temperature must be provided in the hydrogen tank.
Due to the above, a filling controlling logic utilizes the temperature value detected by the temperature sensor when the hydrogen tank is filled with hydrogen so that it is possible to secure a filling safety without exceeding a temperature of 85° C.
In addition, when calculating an amount of fuel, the logic for calculating amount of fuel utilizes the temperature value detected by the temperature sensor so that amount of fuel within the hydrogen tank can be accurately calculated. Since gaseous hydrogen fuel is stored in the hydrogen tank, the temperature value is utilized for calculating amount of fuel in the hydrogen tank.
However, a method utilizing the temperature value detected by the temperature sensor is applied to the filling controlling logic or the logic for calculating amount of fuel.
In this method, since it is overlooked that a temperature value is detected when the temperature sensor is abnormal as well as when the temperature is normal, it is possible that a result of the filling controlling logic and a result of the logic for calculating amount of fuel, which employ the temperature value, are inaccurate and/or unreliable.
As one example, the filling controlling logic controls a process for filling hydrogen with a constant temperature value of 85° C. or less provided by the abnormal temperature sensor so that safety cannot be secured when a filling process is performed.
In addition, since the logic for calculating amount of fuel calculates amount of fuel with a constant temperature value provided from the abnormal temperature sensor, an accuracy of amount of fuel in the hydrogen tank cannot be secured.
However, since the temperature sensor always generates a constant temperature value even in a failure state, there is a limit in judging accurately a failure of the temperature sensor, which can occur at any time.
In particular, even though a failure of the temperature sensor can occur while driving a motor vehicle, it is not verified whether the temperature sensor is normal or abnormal during driving so that this can result in an error in calculation of an amount of fuel.